[goffice] Fix tooltip update for charts. [#693430]

[Jean BrÃfort <jbrefort src gnome org>]

commit 5afedd55b291af0ad06f314a3140daa88e16ae6a
Author: Jean Brefort <jean brefort normalesup org>
Date:   Sat Feb 9 07:12:24 2013 +0100

    Fix tooltip update for charts. [#693430]

 ChangeLog                  |    5 +++++
 NEWS                       |    1 +
 goffice/canvas/goc-graph.c |    1 +
 3 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 2dfe234..517994e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2013-02-09  Jean Brefort  <jean brefort normalesup org>
+
+	* goffice/canvas/goc-graph.c (goc_graph_do_tooltip): force tooltip update.
+	[#693430]
+
 2013-02-07  Morten Welinder  <terra gnome org>
 
 	* goffice/math/go-regression.c (back_solve): Fix infinite loop.
diff --git a/NEWS b/NEWS
index e16bf05..3fa4bd5 100644
--- a/NEWS
+++ b/NEWS
@@ -5,6 +5,7 @@ Jean:
 	* Don't crash after deleting a named smoothed curve. [#691796]
 	* Fix data label offset serialization. [#692305]
 	* Add a user interface for radar and polar plots axis selection. [#692803]
+	* Fix tooltip update for charts. [#693430]
 
 Morten:
 	* Cleanup linear algebra.  [#691630]
diff --git a/goffice/canvas/goc-graph.c b/goffice/canvas/goc-graph.c
index 9afc132..a3f6384 100644
--- a/goffice/canvas/goc-graph.c
+++ b/goffice/canvas/goc-graph.c
@@ -376,6 +376,7 @@ goc_graph_do_tooltip (GocGraph *graph)
 	}
 	gog_chart_map_free (map);
 tooltip:
+	gtk_widget_set_tooltip_text (GTK_WIDGET (item->canvas), NULL);
 	gtk_widget_set_tooltip_markup (GTK_WIDGET (item->canvas), buf);
 	g_free (buf);
 }